Lack of sleep to blame for your midnight munchies

The less you sleep, the more you snack, and a vicious cycle begins. (image) iStock

If you regularly raid the fridge at midnight, you're experiencing what marijuana users call "the munchies".

The clock has just ticked over to one in the morning, but instead of being tucked away in bed you find yourself raiding the fridge for anything to satisfy your sugar cravings.

If that perfectly describes your life, new research published in the journal Sleep says that you're not alone.

In a groundbreaking study, researchers have confirmed that people who are dead tired crave unhealthy snacks like chips and soft drinks much more than those who have had a decent night's rest.

And that's not all – the researchers also found that this practice of "sleep eating" is extremely similar to the "munchies" that cannabis smokers get.

Scientists at the University of Chicago Medical Centre made this breakthrough after studying the eating habits of 14 sleep-deprived but otherwise healthy men and women in their 20s.

To gain their data, the researchers had each of the participants sleep in the Centre's "sleep lab" for two separate four-day stays.

During the first stay, the participants spent on average 8.5 hours in bed each night, and during the day had three square, nutritionally balanced meals.

During the second stay, the wicked researchers gave the participants just 4.5 hours in bed before deliberately waking them up, and offering them high and low calorie snacks.

In each instance the researchers measured the participants' hunger levels, the amount of ghrelin in their system (the hormone that makes you hungry) and their endocannabinoid levels (a group of receptors in your brain that control appetite and mood).

The findings were unequivocal – after restricted sleep, the participants reported a significant increase in hunger levels and a much greater desire to snack on sweet and salty junk food.

After sleeping just 4.5 hours a night, the participants on average consumed an extra 300 calories in snacks, despite eating the same three healthy meals throughout the day.

It's a novel finding that shows how people get into a vicious cycle of poor sleep and poor eating, says Erin Hanlon, who led the study.

"If you have a Snickers bar, and you've had enough sleep, you can control your natural response," Hanlon explained.

"But if you're sleep deprived, your hedonic drive for certain foods gets stronger, and your ability to resist them may be impaired, so you are more likely to eat it. Do that again and again, and you pack on the pounds."

Another surprise conclusion of the study found that the appetite of sleep-deprived souls is similar to those who have been punching cones and lust after the "marijuana munchies".

"Sleep restriction seems to augment the endocannabinoid system, the same system targeted by the active ingredient of marijuana, to enhance the desire for food intake," says Hanlon.

It's potentially a weighty problem for many Australians, who on average only scrape together a paltry seven hours of sleep a night, according to the Sleep Health Foundation.

It's not uncommon for many of us to be restless too, with 35 percent of Aussies reporting that they wake frequently during the night, and 19 percent suffering from a partner's snoring at least several nights per week.